Nah, it's optional for you to fix it, I just have this nagging voice in my head that tell me that I need to tell you.  

Usually I wont bother if the transparency colors only 2 or 3, but since you have plenty of it, It become my obligation to inform you of it 

there no easy way to fix this tho, the only way I can clean it is, to use Eyedropper tool pick the majority transparency colors, and manual delete/paint over the effected area, by crosschecking it using PJ Image Inspector. IDK if it you can also do it with PS or not 

so, i did actually notice this (i run my things through the image tool to check color count) but just ignored those colors since they're effectively the same anyway. is it worth fixing do you think?

i don't have an easy way to fix it in photoshop, but i do have an aseprite license so i think i could fix it by just opening and resaving in that (i'd have to reinstall aseprite since i dont have it on this computer though).

that or write a little program to clean it up, which might be worthwhile anyway (could also strip any accidental png metadata at the same time).